help making a sonic the hedgehog costume

Almost forgotten what he looks like.

Right, off the top of my head... Blue jumpsuit (or blue polo-neck sweatchirt and trackuit pants a size smaller than normal) and spiked blue hair (hair gel and blue hair spray). If you're in Dublin, try the joke shop beside the Gaeity or the art and hobby shop (Dun Laoghaire's particularly good). You could also use some blue pacepaint to paint everything above the eyebrows and bridge of the nose (you might even be able to use the facepaint in the hair if the hairspray's a luxary)

Plain white tennis shows painted with red stripes.